The multiphoton absorption properties of the axially substituted trtrapyrazinoteteaazaporphyrazinato complex, Pyz4TAPInCl are reported and interpreted. The noncolinear optical transmission of the complex and the excited states involved in the noncolinear absorption is determined at the frequency of the second harmonic generation of the Nd:YAG laser in the nanosecond time regime.

The axially substituted complex chloro indium(III) 2-tetrabromo-3-tetra-(3,5-tetra-butylphenytoxy)napthathalocyanine [Br4][([tBu2]PhO).sub.4]NclnC are synthesized. It is shown that the bromination of the napthalocyanine ring considerably improves the limiting properties of such a system when high intensity radiations are produced by nanosecond laser pulses at 532 nm.

The absorption cross-section of colloidal InAs quantum dots of mean radii from 1.6 to 3.45 nm is reported. The radiative lifetime of the first exciton calculated from the oscillator strength increases with dot size and ranges from 4 ns for the smallest dots to 14 ns for the largest ones.